This application relates to a method and apparatus including a dispersement nozzle assembly for dispersing a liquid component throughout a gaseous component to promote heat transfer in a heat exchanger. More specifically, the present invention relates to the combination of such a dispersement nozzle assembly with a plate fin heat exchanger in a process for thermal cracking of hydrocarbons for promoting the establishment of a relatively uniform liquid and gaseous mixture to facilitate and improve heat transfer.
A number of devices and methods for dispersing a liquid component in a gaseous component have been previously proposed. Examples of previously proposed devices and methods for dispersing liquid components within a gaseous medium are described in a number of U.S. patents and a sampling of such patents is set forth below:
U.S. Pat. No. 3,613,333 describes a PROCESS AND APPARATUS FOR CLEANING AND PUMPING CONTAMINATED INDUSTRIAL GASES. The apparatus includes a liquid injecting nozzle or a plurality of nozzles located upstream of a venturi conveying contaminated industrial gas.
The non-analogous U.S. Pat. No. 3,807,145 describes an INJECTOR TYPE COOLING TOWER. FIG. 12 of this non-analogus patent illustrates a scheme whereby a plurality of nozzles extend across the centerline of the narrowest cross-section of a rectangular conduit to partially entrain water in air in a cooling tower for cooling water.
U.S. Pat. No. 3,923,466 describes an APPARATUS FOR THE PRODUCTION OF CRACKED GAS. The apparatus includes a nozzle located upstream of an expansion throat where super-heated steam is mixed with reaction materials.
U S. Pat. No. 4,288,408 describes an APPARATUS FOR THE DIACRITIC CRACKING OF HYDROCARBON feeds for the selective production of ethylene and synthetic gas. A combustible mixture is established by supplying fuel through ports adjacent concentric oxygen ports, which are concentric about a longitudinal axis of the reactor. Feedstock is circumferentially injected into a constriction throat through a plurality of feedstock injectors.
The non-analogous U.S. Pat. No. 4,058,378 describes a HEAT TRANSFER DEVICE for cooling water. The heat transfer device described in this non-analogous patent for cooling water includes a relatively large air duct which is open to ambient air at its upstream end where there is an annular coaxial nozzle to jet hot water through a venturi tube towards the downstream end of the air duct. The high velocity stream of water draws air into the low pressure zone to intermix with the finely divided water droplets moving downstream. In some embodiments, a fan may augment air flow. The water is cooled by a heat transfer of the heat of vaporization as well as by heat transfer from the air itself, whereby water drawn from the downstream end of the air duct is cooled to a temperature suitable for recycling the water.
None of these patents disclose a dispersement nozzle including a venturi throat surrounding an atomizer coaxially mounted within the venturi, which not only improves heat transfer but also improves hydrogen recovery in a process for thermal cracking of hydrocarbons.
A description of a method for thermally cracking hydrocarbons is contained in U.S. Pat. No. 4,548,706, issued Oct. 22, 1985, to Papadopoulos et al which is owned by the assignee of the present application. The disclosure of this patent is incorporated herein by reference.
The method and apparatus of the present invention differs from the known method by providing a method and apparatus for supplying a uniform liquid and gaseous mixture to a heat exchanger in a separation stage in a process for thermal cracking of hydrocarbons in which a nonuniform liquid and gaseous mixture is produced and by providing an improved method to obtain an increased hydrogen rich fraction.